Numerous clinical observations have associated emotional process with changes in respiration. To date, only a very few studies have employed the critical variables of alveolar ventilation, metabolism, or components of the breathing cycle in examining the effects of psychological stress on respiration. Furthermore, none have approached this problem through separation of ventilation into its drive and timing components. Disturbed patterns of respiration, particularly of a hyperventilatory nature, have the potential for producing disabling and selfperpetuating physiological and psychological symptoms. Assessment of the normal respiratory response to stress is essential for an understanding of how ventilatory mechanisms change to yield symptom producing reponses to stress. This is a particularly important question in regard to those individuals with compromised pulmonary functions (asthma, emphysema, etc.) for whom breathing patterns produced or exacerbated by stress could lead to serious respiratory difficulty. We propose to study the effects of task induced psychological stress on respiration. The major goals of the proposed research program include the substantiation of the nature of stress induced respiratory change, identification of the specific respiratory components affected, and investigation as to whether there is a common mode of respiratory response to stress or whether respiratory adjustment is a function of individual response style. Knowledge of precise breathing pattern changes will enhance their revers;ability through therapeutic stress management in both normal individuals and those with compromised pulmonary functions. To this end we will examine the effects of a psychologically stressful task on a number of respiratory variables including ventilatory drive and the timing components of the breathing cycle. These latter two variables are particularly important since change in drive implies a different adaptive mechanism than that in which only timing changes. The stress inducng task will consist of perceptual judgments made under bogus threat of electrical shock. Verification of the manipulation will be made via analyses of changes in heart rate, mood state, and subjective anxiety ratings.